At the present time large amounts of paint are used for yellow traffic marking purposes on highways, parking lots, and the like areas. At present, lead chromate pigment is used to impart the yellow color to such paint and it is stated that some 48 million pounds of lead chromate pigment are used annually to pigment such paint; approximately two pounds of lead chromate pigment per gallon. While excellent from a color point of view, lead chromate is not completely desirable in that it is toxic and also in that it is costly. Consequently, there have been efforts to try to utilize other colorant materials; i.e., pigments and dyes, for yellow traffic marking paint purposes.
These efforts, however, have not been successful to produce a low cost and nontoxic yellow colorant. Either the cost is higher than the lead chromate, the materials are toxic, they fail to give the desired yellow color, and/or they fail to have adequate light-fastness in service. At the present time, government agencies, such as the Federal Highway Administration and state, county, and municipal highway and related agencies, use standards based on the "Highway Yellow Color Tolerance Chart" of the Federal Highway Administration of the U.S. Department of Transportation for yellow traffic marking paints on highways, roads, streets, and the like, and some colorants which are ostensibly low cost and nontoxic fail to meet such standards in the term of color.